Rebalancing the Mk55 "Thud" engine?

[Stoney3K]

The Mk55 "Thud" engine that radially attaches to anything has always been a pet peeve for a lot of people. It's a jack of all trades since you can attach it basically everywhere, has comparatively high thrust, and a high degree of vectoring.

However.... the Thud is excruciatingly heavy for what it does and guzzles fuel. Especially since we now have the Vector that can basically do the same (sans attaching radially), but better.

Which raises the following questions:

• Is there a good use case for a radially-attached LF/O engine with the stats of the Thud? If not, what would be proper stats to make the Thud more useful?
• Would the engine be better off as a Monopropellant-fired service engine, like a large version of the "Puff"? Since the engine already looks like the shuttle's OMS, feeding it with the right fuel and statting it as a properly usable OMS engine would be sensible.
• Are there any other purposes for the engine as it is right now? What would be better improvements on it? Remove it altogether?

Your opinions are welcome. IMO, the Thud already has the looks of an OMS, and feeding it with Monopropellant means we can fly more realistic shuttle mission profiles since the shuttle does not need to carry LF+O on board.

[Wanderfound]

1) Vectors do attach radially, although you'll need to whack a nosecone on top if you want sleek aerodynamics like the Thud.

2) Vectors and Thuds are balanced by science and funds. Thuds are a cheap low tech engine; Vectors are high tech and pricey.

 

Thuds work very well for low-tech Whiplash spaceplanes (and Juno-powered suborbital hoppers). They're also good for lifters that are a bit too heavy for a Skipper but not heavy enough for a Mainsail, or for giving a Mainsail just a bit more kick.

Edited December 14, 2015 by Wanderfound

[GoSlash27]

The Thud is actually an excellent early career engine. A pair of them will outperform a Swivel as a booster, and can lift nearly as much as a Reliant, but have the added capability of thrust vectoring.

They fit very neatly into their family of early career boosters with tier 1 facilities.

The Vector really isn't a fair comparison for any 1.25m engine. It's late tree tech, heavy, expensive, and really too powerful for a 1.25m rocket. It's more comparable to a Skipper or a Mainsail.

Best,

-Slashy

[Red Iron Crown]

I've found the Thud useful for augmenting sea level thrust on long burning core stages where a more vacuum-optimized engine is the main engine. Example:

In this case, the Thuds provide additional thrust and control authority until the rocket gains enough speed for aerodynamic control and gains enough altitude/sheds enough mass for the Rhino to be powerful enough on its own (Thuds turned off by action group after that).